On the first night of the study, participants can eat and drink as they normally would (no dietary intervention). On second and third nights participants will be provided meals, snacks and drinks with specific macronutrient composition, encouraged to only eat and drink study meals, snacks and drinks, and to avoid eating after 10:00 hours. The composition of the study foods and drinks on nights 2 and 3 will be different.

Participants will be provided with meals, snacks and drinks with specific macronutrient compositions and encouraged to only eat and drink study meals, snacks and drinks and to avoid eating after 10:00 hours.

Motor Praxis is a validated neurocognitive test that assesses sensory-motor speed. This test takes approximately 30 seconds to complete and will be measured at two time points (beginning and end of each night shift) in each of the 3 conditions . Differences in accuracy (percentage of correct responses, a higher percentage is better), duration (in milliseconds, lower duration is better), reaction time (in milliseconds, lower reaction time is better) and composite scores (0-1000, higher score is better) will be reported and compared.

Fractal 2-Back is a validated neurocognitive test that assess working memory. This test takes approximately 2 minutes to complete and will be measured at two time points (beginning and end of each night shift) in each of the 3 conditions. Differences in reaction time (in milliseconds, lower reaction time is better) , accuracy (percentage of correct responses, a higher percentage is better) and composite scores (0-1000, higher score is better) will be reported and compared.

Balloon Analog Risk is a validated neurocognitive test that assess risk decision making. This test takes approximately 2 minutes to complete and will be measured at two time points (beginning and end of each night shift) in each of the 3 conditions. Differences in risk propensity (higher scores indicative of greater risk-taking propensity), duration (in milliseconds, lower reaction time is better) and composite scores (0-1000, higher score is better) will be reported and compared.

Psychomotor vigilance test is a validated neurocognitive test that assess vigilant attention. This test takes approximately 3 minutes to complete will be measured at two time points (beginning and end of each night shift) in each of the 3 conditions. Differences in reaction time (in milliseconds, lower reaction time is better), lapses (number, less is better) and composite scores measured (0-1000, higher score is better) will be reported and compared.

Will use validated Stanford Sleepiness Scale (SSS) developed by William C. Dement, M.D., Ph.D. SSS a self-rating scale used to quantify progressive steps in sleepiness at a certain point in time. It is a seven-point Likert-type scale ranging from "feeling active, vital alert, or wide awake" (score = 1) to "no longer fighting sleep, sleep onset soon and having dream-like thoughts" (score = 7). Selected scores by the participants will be reported each time. This test takes approximately 15 seconds to complete. Differences in degree of sleepiness measured at two time points (beginning and end of each night shift) in each of the 3 conditions will be reported and compared.

Work Exhaustion scale, developed and modified by Mickey Trockel MD, PhD, to explore the degree of work related fatigue in residents and fellows. It has 4 questions with a 5 point Likert scale ranging from not at all to extremely. This test takes approximately 30 second to complete. The total score is the average scores of the 4 items and falls between 0 and 4. Scores equal to higher than 1.33 indicate work-related fatigue. Differences in Work Exhaustion scores measured at two time points (beginning and end of each night shift) in each of the 3 conditions will be reported and compared.